What is the ruling of Islam on dealing with cooperatives and insurances that offer the privilege of paying a certain percentage of medicine and treatment expenses in exchange for a monthly sum of money?

Cooperative Takaful insurance is permissible, but commercial insurance based on gharar (uncertainty), gambling, and maysir (games of chance) is forbidden, except for the compelled, who is not allowed to take more than what he paid. Cooperative societies established to assist those affected are permissible if they are free from prohibitions, such as depositing money in usurious banks.